1. Field of the Invention
The present invention relates to a washing method for a charging member by removing deposited materials adhered to the surface of a charging member, employed in an image forming apparatus of an electrophotographic system.
2. Related Art
In an image forming apparatus of an electrophotographic process in which an electrostatic latent image is formed on a photosensitive member and is developed with toner to obtain a toner image, there is widely employed a charging member which follows the rotation of the photosensitive member in contact with the surface thereof, thereby providing the photosensitive member with a charge. Toner and paper dusts tend to be deposited on the surface of such charging member, because it is given a charge at the image formation. Since such deposited substance sticks to the surface of the charging member, the charging ability thereof is lowered, thereby leading likely to an unsatisfactory image quality.
Since such deposited substance is firmly adhered to the surface of the charging member, it cannot be easily removed by a wiping with a dry cloth.
As one of the regeneration methods for the charging member, a method of peeling off a surface layer together with the adhered deposited substance and reforming the surface layer is practiced, but is associated with a drawback of a high process cost. On the other hand, JP-A-6-289755 and JP-A-7-89627 disclose washing methods of employing an organic solvent as a washing liquid and rub-washing the charging member with a brush in the organic solvent or executing ultrasonic washing in the organic solvent.
However, the washing of the charging member with an organic solvent may result in dissolution of the surface film or may cause a serious damage to the surface characteristics of the charging member even if the surface film is not dissolved. Therefore, JP-A-2001-51481 proposes a method of washing the charging member with water. However, because of the weak washing power, this method may be unable to completely remove the deposited substance and smear may remain over the entire surface of the charging member or a part thereof. In such case, the charging member cannot be reused.
The present invention has been made in view of the above circumstances and provides a washing method for a charging member, by removing the deposited substance on the surface thereof, thereby enabling re-use of the charging member.
More specifically, the invention provides a washing method for an electrophotographic charging member to be pressed to a surface of a member to be charged thereby charging the member to be charged, the method comprising a step of washing the surface of the charging member at least once with an acidic aqueous solution.